Combined fog and driving light



Feb. 24, 1942. R. M. (5185 COMBINED FOG AND DRIVENG LIGHT Filed Nov. 30, 1939 Patented Feb. 24. 1942 UNITED STATES PATENT OFFICE COMBINED FOG AND nmvmc ucn'r Robert M. Gibb, Detroit, Mich., assignor to Gen eral Motors Corporation, Detroit, Mich, a corporation of Delaware Application November 30, 1939, Serial No. 306,931

1 Claim.

This invention has to do with the lamps especially useful for driving through fog and articularly with an improved lens for use in such lamps.

Heretofore fog lamps have usually been provided with lenses of amber color because many drivers say that they are able to see better through the fog withyellow light. The yellow light is also considered advantageous because it reduces glare. However the absorption of light by the amber lens cuts down the amount of light thrown on the road and this is objectionable.

According to the present invention the top and bottom zones of the fog lamp are treated to transmit yellow light while the central zone is left uncolored. This is preferably accomplished .by employing a lens with colored top and bottom zones. The arrangement is especially desirable when applied to ,lamps or well-known design in which the light "from the top and bottom zones I is directed downwardly to light the foreground. The beam from the improved lamp consists of colored light illuminating the foreground anda 1936. The top and bottom zones 28 and or the reflector I2 are preferably tilted down as described in the patent to throw the top and bottom light toward the bottom of the beam. The, lens I! is preferably-provided over the top and bottom zones 24' and 28 with an amber colored translucent coating as in the form previously described. In both cases the central zone of thelens is left uncolored.

With the described arrangements all or the light passing through the top and bottom zones of the lens, whether reflected light or light issuing directly from the fllament, is colored yellow. This cuts down the intensity of the light and at the same time it has been found that the colored light reflected from the suspended particles of moisture constituting the fog is less objectionable so that most drivers can-see a greater distance ahead. The colored lens sections likewise cut down the intensity and glare of upwardly directed stray light that might V otherwisebe annoying to anapproaching driver.

concentrated beam of uncolored light directed substantially horizontally to, illuminate the distant road. The colored lens sections also absorb some of the straylight that causes glare and is also particularly objectionable in a fog because it is reflected from suspended particles of moisture, illuminating the fog and making it dlfllcult to see the road. v g

In the drawing:

Figure 1 is a side view partly in section of one form of the improved lamp.

Figure 2 is a rear view of the lens of Figure 1. Figure 3 is a Irontview of a modified design of lamp.

Figure 4 is a side view partly in section of the lamp of Figure 3.

In the form shown in Figures 1 and 2, l0 indicates the lamp housing within which is a reflector l2 equipped with a bulb i4 having a fllament [6 at the focus or the reflector. l8 indi- The invention is capable of considerable modiflcation. Thus instead of so treating the top and bottom zones of the lens, this treatment might be applied to the top and bottom zones.

' otthe reflector. Thecoating could likewise be applied to lenses commonly used with two beam headlamps equipped with conventional reflectors and having down-bending prismsv over the top and bottom zones of the lenses. In such case the 'colored'coating would be applied to these down bending prisms.

While reference has been made to the used amber color. it is obvious that any other color or tint could be employed that will. be effective cates the lens seated on gasket 2| supported by the reflector l2 and held in place by lens ring 22 suitably secured to the housing I0.

In this form of the invention the top and bottom sections 24 and 26 or the lens l8 are coated with translucent material of amber color. This The in reducing glare or improving vision through fog. l

- Various other modifications will occur to those skilled in the art.

I claim: a A combination fog and'driving light comprising: a source of light, a lens and reflector struc- 3 ture surrounding said light source and divided into upper,*lower andintermediate transverselyextending zones, said intermediate zone having means to condense the light intercepted thereby.

into the form of a long-range clear horizontal driving beam, said upper and lower zones having means to depressthe light intercepted thereby into the form of a short-range road beam depressed with respect to the horizontal, and transparent color fllter means associated solely with the upper and lower zones of the lens and reflector structure] to transmit a yellow-tinted depressed beam ior'improved road visibility in foggy weather.

' ROBERT M. GIBB. 

